package com.xxxx.server.config;
import com.xxxx.server.config.security.component.JwtTokenUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
import org.springframework.messaging.support.ChannelInterceptor;
import org.springframework.messaging.support.MessageHeaderAccessor;
import
        org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.util.StringUtils;
import
        org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import
        org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;

/**
 * 聊天功能的实现是为了：工作和生活区分开
 * WebSocket是HTML5开始提供的一种在单个TCP连接上进行全双工通信的协议
 *
 */
@Configuration
//
@EnableWebSocketMessageBroker
public class WebSocketConfig  implements WebSocketMessageBrokerConfigurer{


    @Value("${jwt.tokenHead}")
    private String tokenHead;
    @Autowired
    private JwtTokenUtil jwtTokenUtil;
    @Autowired
    private UserDetailsService userDetailsService;
    /**
     * 添加这个端点Endpoint，这样在网页可以通过websocket连接上服务
     * 也就是我们配置websocket的服务地址，并且可以指定是否使用socketJS
     * @param registry
     */
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        /**
         * 1.将ws/ep路径注册为stomp的端点，用户连接了这个端点就可以进行websocket通讯，支持socketJS
         * 2.setAllowedOrigins("*")：允许跨域
         * 3.withSockJS():支持socketJS访问
         */
        registry.addEndpoint("/ws/ep").setAllowedOrigins("*").withSockJS();
    }
    /**
     * 输入通道参数配置
     * @param registration
     */
    @Override
    public void configureClientInboundChannel(ChannelRegistration registration)
    {
        registration.interceptors(new ChannelInterceptor() {
            @Override
            public Message<?> preSend(Message<?> message, MessageChannel
                    channel) {
                StompHeaderAccessor accessor =
                        MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
                //判断是否为连接，如果是，需要获取token，并且设置用户对象
                if (StompCommand.CONNECT.equals(accessor.getCommand())){
                    //Auth-Token是前端给我们的。
                    String token = accessor.getFirstNativeHeader("Auth-Token");
                    // 判断是否拿到token：不为空则进入if语句.为空吗？不非空=0，为空则1. 非0则1.
                    if (!StringUtils.isEmpty(token)){
                        //拿到完整的token
                        String authToken = token.substring(tokenHead.length());
                        //从token中拿到用户名
                        String username = jwtTokenUtil.getUserNameFromToken(authToken);
                        //token中存在用户名
                        if (!StringUtils.isEmpty(username)){
                            //登录
                            UserDetails userDetails = userDetailsService.loadUserByUsername(username);
                            //验证token是否有效，重新设置用户对象
                            if (jwtTokenUtil.validateToken(authToken,userDetails)){
                                //(用户信息、凭证、权限列表)
                                UsernamePasswordAuthenticationToken authenticationToken =
                                        new UsernamePasswordAuthenticationToken(userDetails, null,
                                                userDetails.getAuthorities());
                                SecurityContextHolder.getContext().setAuthentication(authenticationToken);
                                accessor.setUser(authenticationToken);
                            }
                        }
                    }
                }
                return message;
            }
        });
    }
    /**
     * 配置消息代理
     * @param registry
     */
    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        //配置代理域，可以配置多个，配置代理目的地前缀为/queue,可以在配置域上向客户端推送消息
        registry.enableSimpleBroker("/queue");
    }
}

